FIG. 9 depicts an example of a power semiconductor module which is a semiconductor device used, for example for, electric power control. The power semiconductor module 101 is provided with a metal base 102, a laminated board 103, a semiconductor chip 105, a frame-shaped resin case 106 adhered to the metal base, and an external terminal integrally fixed to the resin case 106.
The external terminal of the power semiconductor module 101 is categorized roughly into two kinds, one of which is a main terminal 107. The main terminal 107 has a main function to flow main electric current via, for example, a main electrode of the semiconductor chip 105. The other is a control terminal. The control terminal has a main function to input a control signal to the control electrode of the semiconductor chip or to direct a signal for detection of the main electric current.
The main terminal 107 is integrally fixed to the resin case 106 by, for example, insert molding. The one end of the main terminal 107 is exposed inside the resin case 106 and electrically connected to the circuit plate of laminated board 103 or to the main electrode of the semiconductor chip 105 by, for example, a bonding wire. The other end of the main terminal 107 is exposed outside the resin case and connected to another apparatus via, for example, a bus bar.
Electric current flowing though the main terminal 107 generates heat in the main terminal 107 due to the electric resistance of the main terminal 107 itself. The heat generation in the main terminal 107 may raise the temperature of the entire power semiconductor module 101. The heat generation in the main terminal 107 may also raise the temperature of another apparatus connected via, for example, a bus bar. As miniaturization and high current density have been required for power semiconductor modules in recent years, it is required to reduce the influence of the heat generation in the main terminal 107.
There is provided a semiconductor device which has a terminal arranged, with intervention of an insulation layer, above an electrical conductive board and is provided with a metal component placed so as to be in contact with the terminal surface on the side of the electrically conductive board (Patent Document 1). However, when multiple main terminals are placed in row, the width of the metal component described in Patent Document 1 is constrained by the insulation distance between the main terminals which has to be secured. Accordingly, heat dissipation from the main terminal is also limited.